“I’ve been putting well for a long time now. [On Friday,] I couldn’t make anything and today the makeable ones went in.

“It’s 18 more holes of good golf [to win] and I just need to take one shot at a time.”

Oosthuizen profited from the ordinary form of the two players he had trailed, with Schwartzel one over for the day as Madalitso Muthiya battled to a par round.

Schwartzel bogeyed two of the first three holes and could not recover, opening the door for Oosthuizen, while Muthiya had two double-bogeys as well as a bogey and five birdies in a wildly inconsistent round.

They were joined in a tie for second by Matt Wallace, who was three under for the day despite his own rollercoaster back nine.